Method of setting level parameters of enemy characters of a computer game and device therefor

ABSTRACT

In a computer role-playing game, the level of an enemy character is set to a proper value in various story developments. When a player character first encounters an enemy character, the level of the enemy character is calculated on the basis of the current level of the player character, and the thus-set level of the enemy character is maintained during the game.

TECHNICAL FIELD

The present invention relates to a method of setting a strength level(hereinafter simply referred to as a “level”) and parameters of an enemycharacter in a computer game in which a player character—which acts inaccordance with operations performed by a player—fights with one or aplurality of enemy characters appearing in the game, and moreparticularly to setting of a level and parameters in a role-playinggame.

BACKGROUND ART

In a certain type of computer games such as adventure games androle-playing games, play progresses in accordance with a story, which inturn follows a scenario. The scenario is composed of a plurality ofsub-scenarios. In a typical adventure game, the story progresses inaccordance with the scenario. For example, when sub-scenarios 1, 2, 3,4, . . . N are provided, the game proceeds In accordance with thesequence of the sub-scenarios 1, 2, 3, 4, . . . N. In such a game, aplayer must sequentially clear the stages corresponding to thesub-scenarios in order to proceed to the next stage. Such a game iscalled a single-scenario-type game.

Meanwhile, a game whose story proceeds according to one of a pluralityof possible scenarios is called a multi-scenario-type game. Whensub-scenarios 1, 2, 3, 4, . . . N are provided, the story can proceedaccording to any of a plurality of possible scenarios, as shown in FIG.1. In FIG. 1, the sub-scenarios enclosed by “{}” are followed in one ofa plurality of possible sequences. That is, the story sometimes proceedsin the following sequence:

sub-scenario 1→sub-scenario 2→sub-scenario 3 and sometimes proceeds inthe following sequence:

sub-scenario 3→sub-scenario 2→sub-scenario 1.

As compared with the single-scenario-type game, the multi-scenario-typegame allows greater flexibility in terms of story development.

Battle, together with story development, lends interest to the game.There are provided scenes in which a player character encounters andfights enemy characters in the course of an adventure. In such a game, aparameter representing the strength of the player character or thestrength of an enemy character is called a “level.”

The level of the player character is increased when the player characterdefeats one or a plurality of enemy characters. The game can be designedsuch that the level of the player character increases in differentmanners depending on the level of the defeated enemy character(s). Forexample, the game may be designed such that in the case of monster A,the level of the player character is increased by one unit when theplayer character defeats ten monsters, and in the case of monster B, thelevel of the player character is increased by one unit when the playercharacter defeats three monsters. If the level of the player characteris increased while the level of the enemy character(s) is maintainedconstant, the difficulty of the game decreases with the progress of thestory. In order to solve such a problem, the level of a newly appearingenemy character is set in accordance with the current level of theplayer character. In the single-scenario-type game, since the storydevelops in ascending sequence of scenario number, the level of theenemy character(s) can be easily set for each sub-scenario. Forexamples, since a player must clear a stage corresponding tosub-scenario n in order to move to the next stage corresponding tosub-scenario n+1, the level of the player is expected to have increasedto some degree when the player has moved to the next stage. Therefore, adesirable result is obtained if the game is designed such that the levelof the enemy character(s) is set in accordance with the increased levelof the player.

However, in a multi-scenario-type game, since the sequence of thesub-scenarios is not constant, and the level of a player at thebeginning of a sub-scenario cannot be predicted, the level of the enemycharacter(s) cannot be set in accordance with the level of the player.Therefore, in the conventional multi-scenario-type game, the level ofthe enemy character(s) is set according to one of the following methods.

Method 1: The level of the enemy character(s) is set in accordance withthe ascending order of scenario numbers.

Method 2: A relative level for each enemy character corresponding to thelevel of the player character is prepared, and for each battle(encounter between the player character and an enemy character) thelevel of an enemy character is set in relation to the level of theplayer character.

In Method 1, the level of the enemy character is set in the same manneras in the single-scenario-type game. In such a setting method, noproblem arises when the story progresses in the sequence ofsub-scenarios 1→2→3→. . . However, when the story progresses in thesequence of sub-scenarios 3→2→1→. . . , the player must fight with a farstronger enemy character from the beginning, making the game difficultfor the player from the beginning. Accordingly, the player can play thegame with interest only when the story proceeds in the sequence ofsub-scenarios 1→2→3→. . . thus making the story the same as in thesingle-scenario-type game.

Method 2 seems good, since the level of each enemy character is set inaccordance with the current level of the player character. For example,when the level of the player character is 5 and the relative level of anenemy character is +1, the level of the enemy character, with which theplayer character fights, becomes 6 (=5+1), so that the player mustalways fight an enemy whose level is one unit higher. The problempresented by this method is that the player loses the fulfillment thatwould otherwise result from the increase in the level of the playercharacter.

That is, when the level of the player character is increased the levelof the enemy character(s) increases accordingly, with the result thatthe enemy character is always stronger than the player character.Therefore, the player is forced to undergo severe battles, and feels noimprovement in his/her skill, with the result that the player losesinterest in the game.

As described above, the conventional method for setting the level ofenemy characters in multi-scenario-type game has drawbacks in that thelevel of a player character is not reflected in the levels of enemycharacters, and the player must always fight enemy characters whoselevels are higher than that of the player character. Therefore, theplayer's skill cannot be reflected in the game, and therefore the playercannot experience fulfillment and satisfaction, so that the playereventually loses interest in the game itself.

The ideal story development in a computer game is such that as the levelof a player character increases the level of enemy characters alsoincreases, and such that an increase in the level of the player isdirectly reflected in the game. For example, there develops a situationin which a player first fights a relatively weak enemy character, andwhen the player defeats the enemy character, the player feels that theplayer character has became stronger. After the story develops in thismanner for a certain period of time, the player seeks a stronger enemycharacter.

An object of the present invention is to provide a method of setting thelevel of an enemy character in such a way that the story develops in theabove-described ideal manner In a multi-scenario-type computer game.

DISCLOSURE OF THE INVENTION

The present invention provides a method of setting the level of an enemycharacter in a computer game in which a player character—which acts inaccordance with operations of a player—fights with one or a plurality ofenemy characters who appear in the game, wherein when the playercharacter first encounters an enemy character, the level of the enemycharacter is calculated on the basis of the current level of the playercharacter, and the thus-set level of the enemy is maintained during thegame.

In the present invention, the difference, upon first encounter, betweenthe level of an enemy character and the level of the player character iscalled a “basic relative level,” and the level of the enemy is obtainedas follows:

(Level of an enemy character)=(Level of the player character)+(Basicrelative level)

However, when necessary, the calculated level of the enemy character isrestricted to a predetermined upper or lower limit.

Specifically, the level of an enemy character is represented by use of aset of parameters respectively representing physical strength, offensiveskill, defensive skill, quickness, etc. The enemy character's fixedlevel or set of parameters is generally maintained constant. A separateset of parameters is preferably prepared for each of a plurality oftypes of enemy characters. FIG. 2 shows the relationship between thelevel of an enemy character and the level of the player character. InFIG. 2, L_(p) represents the level of the player character, L_(Ek)represents the level of an enemy character k, and P_(k) represents apoint where the player character first encounters the enemy character.Although the level of the player character does not increase at aconstant rate (i.e., along a straight line) as shown in FIG. 2, thestrength of the player character generally increases as the storyprogresses.

In the multi-scenario-type game, the time when the player characterencounters an enemy character changes depending on the scenario. In thepresent invention, the level of an enemy character is set on the basisof the level of the player character upon first encounter. Therefore,different levels are set for different enemy characters of the sametype, depending on the time of the first encounter, which variesdepending on the scenario.

The set of parameters specifically representing the strength of an enemyis calculated on the basis of the level. Each of the parameters isdetermined through calculation by use of a function whose argument isthe level, or through selection of values from a table. When the game isdesigned to set different values for the parameters depending on thelevel, an enemy character can have completely different characteristicsdepending on the scenario.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an example progression of a conventionalmulti-scenario-type game.

FIG. 2 is a diagram showing the relationship between the level of theplayer character and the levels of enemy characters.

FIG. 3 is a flowchart according to an embodiment of the presentinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 3 is a flowchart according to an embodiment of the presentinvention. In the present invention, when the player character firstencounters an enemy character, the level of the enemy character is set(judgment D3 and processing step S5). Subsequently, on the basis of thethus-determined level, a set of parameters representing the strength ofthe enemy character is calculated (judgment D3 and processing step S6).

That is, the set of parameters representing the strength of the enemycharacter is calculated upon first encounter, and is maintained constantthereafter. The set of parameters representing the strength of the enemycharacter is determined on the basis of the level L_(E). However, sincethe level L_(E) and the parameters are fixed for each type of enemycharacter, the processing must be performed such that in first encounterjudgment D3 a judgment is made as to whether the encounter with enemycharacter k is the first, and the level set by the processing step S5must be represented as L_(EK). In FIG. 2, the type of enemy is omittedfor simplification.

In the present invention, the level of an enemy character is set on thebasis of the level L_(P) of the player character upon first encounter.That is,

L _(EK) =f _(k)(L _(P)).

Here, f_(k) is an appropriate function for the enemy character k whichdepends on L_(P). For example, the function f_(k)(L_(P)) can beexpressed as follows through use of a basic relative level L_(ER) (whereL_(ER) is a constant):

f _(k)(L _(P))=L _(P) +L _(ER).

In this case, when the basic relative level L_(ER) is 2 and the levelL_(P) of the player character upon first encounter with the enemy is 10,the level of the enemy character becomes 12. That is, the level of theenemy character changes depending on the manner in which sub-scenariosare selected. This will be better understood from the following example.

A story is assumed to develop in accordance with a scenario composed ofsub-scenarios A, B, C, and D, whose sequence can be freely selected, andthe basic relative level of the enemy character X is +5. It is alsoassumed that player 1 has followed the sub-scenarios in the sequence:

A→B→C→D,

and player 2 has followed the sub-scenarios in the sequence:

D→C→B→A.

Since player 1 selected the sub-scenario A at an early stage, the levelof the player 1 appears to be low. If the level of a player characterfor the player 1 is 5 at the time when the sub-scenario A is selected(when the player character first encounters the enemy character X), thelevel of the enemy character X is 10. Meanwhile, player 2 has reachedthe sub-scenario A after clearing the stages corresponding to thesub-scenarios D, C, and B, during which time the level of player 2 hasincreased.

Assuming that the level of a player character for player 2 is 15 uponfirst encounter with the enemy character X at a stage corresponding tothe sub-scenario A, the level of the enemy character X becomes 20. Thatis, a weak enemy character X appears for the player charactercorresponding to player 1, while a strong enemy character X appears forthe player character corresponding to player 2. As described above, thesame enemy character may have different levels depending on the player.

In relation to setting the level of the enemy character, upper and lowerlimits are preferably provided in order to avoid setting of an extremelevel. That is, when the upper limit is represented by L_(Emax) and thelower limit is represented by L_(Emin), the level L_(E) of the enemycharacter is calculated as follows:

when L _(E) >L _(Emax) ,L _(E) =L _(Emax)

when L _(E) <L _(Emin) ,L _(E) =L _(Emin)

Similarly, upper and lower limits are set for the level of the playercharacter. Thus, it becomes possible to prevent a player's intentionaloperation of needlessly increasing the level of the player characterthrough continuous fighting weak enemies, as well as a player'sintentional operation of continuously causing the game program to createweak enemies by running about trying to escape an encountered enemy.

The factors that actually represent the strength of an enemy characterinclude physical strength, offensive skill, defensive skill, quickness,etc. These factors will be called parameters. The parameters arecalculated on the basis of the level of the enemy character. Since thevalues of the parameters are obtained by processing step S6 in theflowchart of FIG. 3 on the basis of the level of the enemy character,the value Q_(Em) of parameter m is calculated as follows:

Q _(Em) =g(L _(E)).

Although g represents a function, in the actual program, Q_(Em) may beobtained, not through use of a simple calculation formula, but throughcombined use of a table and the function. Once the Q_(Em) and L_(E) areset, these values are maintained constant during the game. Especially,by changing set values of Q_(Em), the characteristics of the enemycharacter can be set to totally different characteristics in accordancewith the selection sequence of the sub-scenarios. Therefore, each playercan be provided with a completely different game.

The battle in processing step S7 corresponds to a fight with an enemycharacter. In this case, the player can select an option of running awaywithout fighting. According to a conventional game, the action ofrunning away can be used as a strategic action in which a playercharacter is caused to encounter enemy characters during a period inwhich the level of the player character is still low, to thereby set thelevels of all enemy characters to low values, and subsequently the levelof the player character is increased, with the result that the playercharacter always fights weak enemies. If the above-described method isused, only weak enemies can be created. In order to solve such aproblem, a lower limit is set, and the level of the enemy character isprevented from becoming lower than the lower limit.

Processing S9 increases the level of the player character when theplayer character defeats an enemy character during a battle. In theflowchart, a simple judgment is made as to whether the player characterhas defeated the enemy (judgment D4). However, the judgment D4 and theprocessing step S9 are performed differently depending on the type ofthe enemy character. For example, the level of the player character isincreased by one unit when the player character defeats 10 enemycharacters k, and is increased by two units when the player characterdefeats 5 enemy characters s. Further, when the player character failsto defeat the enemy character (e.g., when the player character runs awayor is damaged), the processing S8 step updates the parameters (includingthe level) of the player character. In general, when the playercharacter runs away without taking any action, the parameters of theplayer do not change.

As described above, the story of the game is developed sub-scenario bysub-scenario; the level of the enemy character changes depending on thesequence of selected sub-scenarios; and the parameters determinedaccording to the level change accordingly. Therefore, each player canenjoy a game which is uniquely modified for the player.

As an embodiment of the present invention, an example of a method ofsetting the level of an enemy character and various parameters will bedescribed. When the lower limit for level LV is 1 and the upper limitfor the level LV is 100, a parameter K for physical strength isintroduced in accordance with the following equations:

K=(4^(a))+30

a=INT(LV/15)+2

The K corresponding to each level is represented by the following table.

Level of enemy character Constant (K)  1 ≦ LV < 15   46 15 ≦ LV < 30  94 30 ≦ LV < 45  286 45 ≦ LV < 60  1054 60 ≦ LV < 75  4126 75 ≦ LV <90 16414  90 ≦ LV < 100 65566

When the lower limit for level LV is 1 and the upper limit for the levelLV is 100, a parameter K for each of offensive skill, defensive skill,and quickness is introduced in accordance with the following equations:

K=a×10+50

a=INT(LV/20)

Parameter K corresponding to each level is represented by the followingtable.

Level of enemy character Constant (K)  1 ≦ LV < 20 50 20 ≦ LV < 40 60 40≦ LV < 60 70 60 ≦ LV < 80 80  80 ≦ LV < 100 90

These parameters are stored and used when the player characterencounters an enemy character again.

In the present invention, the parameters of an enemy character are setupon first encounter. Therefore, even if the player first feels that anenemy character is strong, the player feels that the enemy character isweak when the level of the player character has increased with progressof the story, or when the player character again fights a previouslyencountered enemy character, so that the player can feel that his/herskill has improved. At the same time, the player is satisfied withhis/her skill.

In the method of the present invention, the level of an enemy characterchanges depending on the sequence of selected sub-scenarios, and asdescribed in the embodiment, the same enemy character can be caused toappear to have completely different characteristics, depending on themanner of setting the parameters. Therefore, even if an enemy characterX is a very weak monster for a player A, to a player B the enemy mayappear to be nimble and to have great offensive skill. Also, a player Cmay feel that the same enemy character was difficult to defeat althoughthe enemy character is dull and has weak offensive skill. The differencein impressions among the players occurs because, depending on the timewhen the player character encounters the enemy character, the level ofthe player character changes and the parameters of the enemy characterare set to completely different values. As described above, each playercan create his/her own unique game.

INDUSTRIAL APPLICABILITY

The method according to the present invention is particularly effectivein computer games, such as role-playing games and adventure games, inwhich a player character fights with enemy characters and the storydevelops in accordance with one of a plurality of scenarios, eachscenario comprising a series of sub-scenarios. For example, when aplayer resets a computer to re-start the game and follows a differentscenario, the player can perceive the game to be much different from thepreviously played game. An especially great effect is attained inrole-playing games. In a conventional game, once the game has beenfinished, the player can read the story development in a second orsubsequent play, with the result that the player loses interest in thegame. By contrast, in the game created in accordance with the presentinvention, since the characteristics of each enemy character change inaccordance with the manner in which sub-scenarios are selected, theplayer can enjoy the same game in several different ways at differenttimes. Further, it is possible to prevent the case where the intendedstory is lost due to an intentional operation that the author of thegame did not intend for the player to pursue.

What is claimed is:
 1. A method of executing a computer game including aplayer character which acts in accordance with operations of a playerand fights with one or a plurality of enemy characters who appear in thegame, said method comprising: calculating a level of an enemy characterbased on a current level of the player character when the playercharacter first encounters the enemy character; setting the level of theenemy character in accordance with a result of the calculating step; andmaintaining the set level of the enemy character during the computergame.
 2. A computer game device including a player character which actsin accordance with operations of a player and fights with one or aplurality of enemy characters who appear in the game, said devicecomprising: means for calculating a level of an enemy character based ona current level of the player character when the player character firstencounters the enemy character; means for setting the level of the enemycharacter in accordance with a result of the calculating means; andmeans for maintaining the set level of the enemy character during thegame.
 3. A computer program product for executing a computer gameincluding a player character which acts in accordance with operations ofa player and fights with one or a plurality of enemy characters whoappear in the game, said computer program product comprising: a firstcomputer code configured to calculate a level of the enemy characterbased on a current level of the player character when the playercharacter first encounters the enemy character; and a second computercode configured to set the level of the enemy character in accordancewith a result of the first computer code; and a third computer codeconfigured to maintain the set level of the enemy character during thegame.
 4. A method of executing a computer game including a playercharacter which acts in accordance with operations of a player andfights with one or a plurality of enemy characters who appear in thegame, said method comprising: calculating a level of an enemy characterwithin a predetermined range and based on a current level of the playercharacter when the player character first encounters the enemycharacter; setting the level of the enemy character in accordance with aresult of the calculating step; and maintaining the set level of theenemy character during the computer game.
 5. A computer game deviceincluding a player character which acts in accordance with operations ofa player and fights with one or a plurality of enemy characters whoappear in the game, said device comprising: means for calculating alevel of an enemy character within a predetermined range and based on acurrent level of the player character when the player character firstencounters the enemy character; means for setting the level of the enemycharacter in accordance with a result of the calculating means; andmeans for maintaining the set level of the enemy character during thegame.
 6. A computer program product for executing a computer gameincluding a player character which acts in accordance with operations ofa player and fights with one or a plurality of enemy characters whoappear in the game, said computer program product comprising: a firstcomputer code configured to calculate a level of the enemy characterwithin a predetermined range and based on a current level of the playercharacter when the player character first encounters the enemycharacter; and a second computer code configured to set the level of theenemy character in accordance with a result of the first computer code;and a third computer code configured to maintain the set level of theenemy character during the game.
 7. A method of executing a computerrole-playing game including a player character which acts in accordancewith operations of a player and fights with one or a plurality of enemycharacters who appear in the game, said method comprising: calculating alevel of an enemy character within a predetermined range and based on acurrent level of the player character when the player character firstencounters the enemy character; setting the level of the enemy characterin accordance with a result of the calculating step; and maintaining theset level of the enemy character during the computer game.
 8. A computerrole-playing game device including a player character which acts inaccordance with operations of a player and fights with one or aplurality of enemy characters who appear in the game, said devicecomprising: means for calculating a level of an enemy character within apredetermined range and based on a current level of the player characterwhen the player character first encounters the enemy character; meansfor setting the level of the enemy character in accordance with a resultof the calculating means; and means for maintaining the set level of theenemy character during the game.
 9. A computer program product forexecuting a computer role-playing game including a player characterwhich acts in accordance with operations of a player and fights with oneor a plurality of enemy characters who appear in the game, said computerprogram product comprising: a first computer code configured tocalculate a level of the enemy character within a predetermined rangeand based on a current level of the player character when the playercharacter first encounters the enemy character; and a second computercode configured to set the level of the enemy character in accordancewith a result of the first computer code; and a third computer codeconfigured to maintain the set level of the enemy character during thegame.